I haven't tested this, but apparently if you hit Ctrl to hold control you can order them.
However, if you hold control while looking at the cards it does NOT work and at the very least this should be fixed. Otherwise you have to put an end of turn stop for yourself and your opponents constantly.
Lastly, if the arena dev's don't want to change this, it should by default arrange the cards on the bottom of your library from highest mana value at the top to lowest mana value at the bottom.
I haven't tested this, but apparently if you hit Ctrl to hold control you can order them.
However, if you hold control while looking at the cards it does NOT work and at the very least this should be fixed. Otherwise you have to put an end of turn stop for yourself and your opponents constantly.
Lastly, if the arena dev's don't want to change this, it should by default arrange the cards on the bottom of your library from highest mana value at the top to lowest mana value at the bottom.